This application claims benefit of Japanese Application Nos. 2001-22202, filed in Japan on Jan. 30, 2001; 2001-43785, filed in Japan on Feb. 20, 2001; and 2000-363641, filed in Japan on Nov. 29, 2000, the contents of which are incorporated by this reference.
1. Field of the Invention
This invention relates to an ultrasound transducer array, used in ultrasound diagnosis for medical use or for non-destructive inspection.
2. Description of the Related Art
In recent years, ultrasound diagnostic equipment using ultrasound transducers has come into widespread use in medical diagnostics and other fields. In addition to mechanical scanning-type ultrasound transducers which rotate a single ultrasound transducer or similar to mechanically scan with ultrasound, electronic scanning-type ultrasound transducers have also been adopted.
Such electronic scanning-type ultrasound transducers are formed using ultrasound transducer arrays, in which ultrasound transducers are formed in an array shape.
Conventional electronic scanning-type ultrasound transducers (ultrasound transducer arrays) provide signal electrodes and ground electrodes on each side of a piezoelectric element, and one or more grooves, extending to a depth partway through a provided matching layer, to divide the element and form a plurality of elements. Here, the ground electrodes must be connected to a common line.
As a method of connecting the ground electrodes to a common line, the matching layer adjacent to the piezoelectric element may be made of a conductive resin, and grooves are provided being extended to a depth midway through the matching layer, as in Japanese Unexamined Patent Application Publication No.61-253999.
However, if the thickness of the remaining matching layer is small, the strength of the matching layer is relatively weakened, so that when a force is applied, cracks may appear in the matching layer, or conduction faults may occur.
On the other hand, if the thickness of the remaining matching layer is large (if the groove cut into the matching layer is shallow), cross talk may occur, and the image quality may worsen.
An object of this invention is to provide a progressive ultrasound transducer array, which prevents the occurrence of cross talk and in which a common connection of the ground electrodes of piezoelectric elements can be reliably secured.
In this invention, an ultrasound transducer array, in which are arranged a plurality of piezoelectric elements, which can be electrically operated independently, comprises one or a plurality of matching layers, provided on the acoustic radiating surface side of the above piezoelectric elements; a conductive material layer, provided on the side of the above matching layers joined with the above piezoelectric elements, in the direction along the array direction, part of which is in contact with and electrically connected to the above piezoelectric elements along the above array direction, and part of which is not in contact with the above piezoelectric elements along the above array direction; a plurality of grooves, which mechanically and electrically insulate at least part of the above piezoelectric elements and the above matching layer for each element which can be electrically operated independently; and, conductive material which fills at least a part of the portions of the above grooves which are formed where the above piezoelectric elements and the above conductive material layer are not in contact.